Inflatable curtain and method for placing an inflatable curtain in a stored condition

Abstract

An apparatus ( 10 ) helps to protect an occupant ( 28 ) of a vehicle ( 12 ) that has a side structure ( 16 ) and a roof ( 18 ). The apparatus ( 10 ) includes an inflatable vehicle occupant protection device ( 14 ) that has a stored condition for being positioned along the vehicle roof ( 18 ). The protection device ( 14 ) is inflatable away from the vehicle roof ( 18 ) to a deployed condition positioned between the side structure ( 16 ) and a vehicle occupant ( 28 ). The protection device ( 14 ) includes an upper edge portion ( 30 ) for being connected to the vehicle along the vehicle roof ( 18 ). A lower edge portion ( 38 ) of the protection device ( 14 ) is folded over onto itself at least once in the stored condition. The protection device ( 14 ), when in the stored condition, has a rolled-up configuration such that the folded over lower edge portion ( 38 ) occupies a central space ( 116 ) bounded by the rolled-up portion ( 114 ) of the protection device.

Having described the invention, we claim the following: 
     
       1. A method for placing an inflatable vehicle occupant protection device in a stored condition, method comprising the steps of:
 providing an inflatable vehice occupant protection device having an upper edge portion for being connected to a vehicle along a vehicle roof and an opposite lower edge portion; 
 folding the lower edge portion over onto itself at least once; and 
 rolling the protection device up such that the folded over lower edge portion occupies a central space surrounded by the rolled up portion and such that the folded over lower edge portion maintains the folded condition and overlying folded over portions of the folded over lower edge are free from being rolled up with the surrounding rolled up portion of the protection device. 
 
     
     
       2. The method recited in  claim 1 , wherein the step of folding the lower edge portion comprises folding the lower edge portion in a z-fold configuration comprising at least two folds in opposite directions. 
     
     
       3. The method recited in  claim 1 , wherein the step of folding the lower edge portion comprises folding the lower edge portion in a single fold configuration such that the single folded portion occupies multiple layers of the rolled up portion. 
     
     
       4. The method recited in  claim 1 , wherein, during the step of rolling the protection device, the folded over lower edge portion is not distorted by the rolled up portion. 
     
     
       5. An air bag folded and rolled according to the method of  claim 1 . 
     
     
       6. The method recited in  claim 1 , wherein the step of rolling the protection device comprises preventing the folded over lower edge portion of the protection device from conforming to the curved configuration of the surrounding rolled up portion of the protection device. 
     
     
       7. An apparatus for helping to protect an occupant of a vehicle that has a side structure and a roof, the apparatus comprising:
 an inflatable vehicle occupant protection device having a stored condition for being positioned along the vehicle roof, the protection device being inflatable away from the vehicle roof to a deployed condition positioned between the side structure and a vehicle occupant, the protection device comprising: 
 an upper edge portion for being connected to the vehicle along the vehicle roof and an opposite lower edge portion, the lower edge portion being folded over onto itself at least once in the stored condition of the protection device, the protection device when in the stored condition having a rolled-up configuration such that the folded over lower edge portion occupies a central space bounded by the rolled-up portion of the protection device, the folded over lower edge portion being configured in the central space to maintain a folded condition and overlying folded over portions of the folded over lower edge are free from being rolled up with the surrounding rolled up portion of the protection device. 
 
     
     
       8. The apparatus recited  claim 7 , wherein the folded over lower edge portion has a z-fold configuration comprising at least two folds in opposite directions. 
     
     
       9. The apparatus recited in  claim 7 , wherein the folded over lower edge portion has a single fold configuration, the roll being configured such that the single folded portion occupies multiple layers of the rolled-up portion. 
     
     
       10. The apparatus recited in  claim 7 , wherein the folded over lower edge portion is maintained in the central space such that the rolled-up portion does not distort the folded over lower edge porton. 
     
     
       11. The apparatus recited in  claim 7  wherein the protection device is configured and arranged such that the folded over lower edge portion of the protection device does not conform to the curved configuration of the surrounding rolled up portion of the protection device.